Leadership is an influence process that centers on group members being motivated to reach collective goals. As such, it is ultimately proven by followership. Yet this is something that classical and contemporary approaches struggle to explain as a result of their focus on the qualities and characteristics of leaders as individuals in the abstract. To address this problem, we outline a social identity approach that explains leadership as a process grounded in an internalized sense of shared group membership that leaders create, represent, advance, and embed. This binds leaders and followers to each other and is a basis for mutual influence and focused effort. By producing qualitative transformation in the psychology of leaders and followers it also produces collective power that allows them to coproduce transformation in the world. The form that this takes then depends on the model and content of the identity around which the group is united.